diff --git a/doc/api/esm.md b/doc/api/esm.md
index 551eef604eac0e..357226d7a690e4 100644
--- a/doc/api/esm.md
+++ b/doc/api/esm.md
@@ -674,6 +674,12 @@ CommonJS entry point for `require`.
 }
 ```
 
+The above example uses explicit extensions `.mjs` and `.cjs`.
+If your files use the `.js` extension, `"type": "module"` will cause such files
+to be treated as ES modules, just as `"type": "commonjs"` would cause them
+to be treated as CommonJS.
+See [Enabling](#esm_enabling).
+
 ```js
 // ./node_modules/pkg/index.cjs
 exports.name = 'value';